Question: Which of these numbers is composite? ${13,\ 37,\ 65,\ 73,\ 97}$
A composite number is a number that has more than two factors (including 1 and itself). 13, 37, 73, and 97 each have only two factors. The factors of 65 are 1, 5, 13, and 65. Thus, 65 is the composite number.